You can use the link and mirroring column to get data from other boards. For instance, you can have one project set up with all the dependecies at board level. If one task depends on other project, you can link that activity to the ones related in the other project and get also its timeline view. Then, you can compare both timelines and update the dependent one when needed. In this example I should update “Manufacture products” pushing it one day.
At this time, it’s not possible to manage mirrored columns with automations so you will have to perform the comparasion and updates manually.